Add .allowExcessArguments() and error message

[shadowspawn]

Pull Request

Problem

By default, excess arguments are silently ignored. Checking manually is a bit tricky.

See: #259 #749 #1000 #1268

Solution

• add a check for excess arguments before calling action handler
• .allowExcessArguments() is like .allowUnknownOption() to enable/disable the new error
• off by default (for now), but will be on by default for CommandStrict, see WIP: CommandStrict #1404

Like missing arguments, only checked if there is an action handler.

ChangeLog

• .allowExcessArguments() to control whether excess arguments are allowed for command (Add .allowExcessArguments() and error message #1407)

Later

I have not added to the README yet and will do that separately. (Hopefully in combination with CommandStrict if that works out.)

[shadowspawn]

Example

const { program } = require('commander');

program
  .arguments('<file')
  .allowExcessArguments(false)
  .action(() => {
    console.log('Called main action handler')
  });

program
  .command('sub <first> <second>')
  .allowExcessArguments(false)
  .action(() => {
    console.log('Called subcommand action handler')
  });

program.parse();

$ node foo.js alpha beta
error: too many arguments. Expected 1 argument but got 2.
$ node foo.js sub alpha beta
Called subcommand action handler
$ node foo.js sub alpha beta gamma
error: too many arguments for 'sub'. Expected 2 arguments but got 3.

[abetomo]

Are the default parameters available?

allowExcessArguments(allowExcess = true) 

[shadowspawn]

Good question, I'll look into that. We have a few methods with this sort of pattern that could use it. Likely can because we have moved forward our minimum version of node.

[shadowspawn]

Defaults from node 6, which is our minimum supported version: https://node.green/#ES2015-syntax-default-function-parameters

[shadowspawn]

Added default parameter instead of manual test to multiple routines.

[abetomo]

Thank you for fixing it.

[abetomo]

Great!